HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

_D_S_J_R_ wrote: ↑Tue Jul 30, 2019 10:06 pm The AP20 transformer is rather larger than the A20 type (around 60% greater capacity) and the difference to me was clearly audible on more 'spirited' music in my experience comparing to the A20.

Get a pair of 100dB/W speakers then

Raul_77 wrote: ↑Tue Jul 30, 2019 8:52 pm ...Yes, there is the AP20, but I consider it too expensive, as it offers the same as the P20+A20 with a few more entries. It would be good to convert it into an AP30 by increasing the power somewhat....

The AP30 was stopped because the AP20 is the same as it only build in a smaller case.

Somebody thinks the AP20 is too expensive. I have heard it all now.

The range is too bloated (IMO). Some of the models need to go to help simplify the business for Tom and Paul which will help keep the prices down.

Raul_77 wrote: ↑Tue Jul 30, 2019 8:52 pm About personalization, there are brands like Audion (https://www.audion.co.uk/) that offer them in their products. For example, one could buy a standard AP50 or a SE (Special Edition), the difference could be better electrolytic capacitors, better volume potentiometer and special resistors in the feedback, the price difference would be for the improved components, the assembly work is the same.

I don't understand why NVA should do that, it doesn't fit in NVA ethos and spirit.

Doesn't make any difference either according to the man himself, who gave me some used DNM slit-foil caps he'd removed from older units for repair/updating (he fitted them back then as they were all the rage and nothing to do with any perceived sonic benefit in the NVA design). A better quality pot is covered by the SA upgrade (the stock one is seriously good compared to posher looking more costly alternatives) and I don't think much feedback is used at all (he once told me) if you read measurement reviews around and about, admittedly on older versions (same circuit though).

If it isn't broken then no need to fix it.

With amps i have fiddled with the feedback resistor and cap were always the first to be compared to others as they were usually the ones most sensitive to change. Next in line would be the input coupling cap but the nva doesn't have one of those . The front end decoupling caps were next in the hierarchy. The nva circuit shares much with other designs but there are quite a few differences.

I think we should all trust the decisions the doc made and not spoil the brew. Of course if somebody wants to mess about themselves then that is up to them. The circuit has some oddities that means modifications may result in the magic smoke (imo).

Also you can't change the bias on the fly as this is set by a resistor. Means changing that resistor. I suspect Doc thought bias pots were the work of the devil and a resistor was more purist. So any changes to the board that affects bias will need a resistor swap. All imo ofc.

_D_S_J_R_ wrote: ↑Wed Jul 31, 2019 8:45 am Doesn't make any difference either according to the man himself, who gave me some used DNM slit-foil caps he'd removed from older units for repair/updating (he fitted them back then as they were all the rage and nothing to do with any perceived sonic benefit in the NVA design). A better quality pot is covered by the SA upgrade (the stock one is seriously good compared to posher looking more costly alternatives) and I don't think much feedback is used at all (he once told me) if you read measurement reviews around and about, admittedly on older versions (same circuit though).

Oh dear many years ago when these dreadful Slit-Foil cap came out (1980's) I was asked by Martin Collums to check them out, I was disappointed as the ESR and peak current test and ripple current test were to be blunt shit. I would never recommend these bloody things. For PSU;s designs it would be a big mistake.

Firebug1 wrote: ↑Wed Jul 31, 2019 7:46 am

Raul_77 wrote: ↑Tue Jul 30, 2019 8:52 pm About personalization, there are brands like Audion (https://www.audion.co.uk/) that offer them in their products. For example, one could buy a standard AP50 or a SE (Special Edition), the difference could be better electrolytic capacitors, better volume potentiometer and special resistors in the feedback, the price difference would be for the improved components, the assembly work is the same.

I don't understand why NVA should do that, it doesn't fit in NVA ethos and spirit.

You are correct.

Richard's skill was to create designs that do not need 'boutique' parts. Of course, there can be differences, and that's why there are things like the SA preamps in the range, but, much of the desire from enthusiasts to change components, sometimes to the point where the item no longer resembles the original design, is down to what I would describe as 'audiophile nervosa'. Follow that path and you end up with £1500 mains leads and £150 fuses.

Each to their own, of course (it's your money), but it's not what NVA is about.

A bit late to this, but pleased the brand is continuing!